D36. Early Posterior Vault Distraction Osteogenesis is changing the Syndromic Craniosynostosis Treatment Paradigm: Outcomes of A 20-year Cohort Study

PURPOSE: We assessed the impact of early posterior vault distraction osteogenesis (PVDO) on operative patterns and surgical burden compared to conventional treatment paradigms for syndromic craniosynostosis. METHODS: We retrospectively reviewed patients with syndromic craniosynostosis treated at our institution from 2000 to 2023 with minimum 5-year follow-up. Patients were divided into those who underwent early PVDO (2009 onwards) or conventional vault reconstruction (before 2009). A subgroup analysis was performed in patients with minimum 8-year follow-up. RESULTS: Fifty-four patients met inclusion criteria (31 PVDO, 23 non-PVDO). Mean age at initial cranial vault procedure was similar between cohorts (1.0 vs. 1.1 years, p>0.05), as were cephalic indices (p>.05). Kaplan-Meier analysis demonstrated that fronto-orbital advancement and remodeling (FOAR) procedures were delayed to an older age in the PVDO cohort (2.3±1.6 vs. 1.1±0.7 years; p<.001). Repeat FOAR was performed in only one (9%) PVDO patient at age 8.7 years versus 18 (60%) conventionally treated patients at age 5.8±3.1 years (p=.004). In Apert and Crouzon syndromes, only two (14%) PVDO patients underwent FOAR prior to midface advancement, compared to all 12 conventionally treated patients. Patients with Muenke and Saethre-Chotzen syndromes underwent an increased number of total vault procedures in their respective PVDO cohorts. CONCLUSION: For patients with syndromic craniosynostosis, early PVDO is associated with fewer and later FOAR procedures, and reduced need for revisionary fronto-facial procedures.